Sustainable management of SEAR waste emulsions from lindane production by electrochemical oxidation: performance and environmental implications

Surfactant-enhanced aquifer remediation (SEAR) generates waste emulsions containing persistent chlorinated organic compounds (COCs) and surfactants which pose serious environmental challenges. This study evaluates the electrochemical oxidation of actual SEAR waste emulsions from lindane production using boron-doped diamond (BDD) and mixed-metal-oxide (MMO) anodes as sustainable treatment options. The degradation of 26 target COCs, total organic carbon (TOC) removal, toxicity reduction, and residual surfactant capacity (SC) were comparatively assessed to balance pollutant abatement and resource recovery. BDD achieved near-complete mineralization and detoxification (>98 % TOC removal), whereas MMO enabled partial oxidation and preserved up to 71 % of the SC, allowing potential surfactant reuse. The results demonstrated a process-level trade-off between complete detoxification and circular reuse potential, providing new insight into the environmentally safe management of industrial remediation effluents. These findings support the integration of electrochemical processes into sustainable waste management frameworks for contaminated site remediation.